Improvement in gas-motor engines



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GAS-MOTOR ENGINES. No. 194,047. .Patented Aug.14,1s77.

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No. 194,047. Patented Aug.14,1877.

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.IRL uilllllulllll N www N. PETERS, PHuTo-LITHOGRAPHE UNITED STATES PATENT OQFFIGE.

NIOOLAUS A. OTTO, OF DEUTZ, GERMANY.

IMPROVEMENT IN GAS-MOTOR ENGINES.

Specication forming part of Letters Patent N o. 194,047, dated August 14, 1877; application filed July ,13,1816.

To all whom it may concern:

Be it known that l, NIGOLAUS AUGUST OTTO, of the Gas-Motoren Fabrik-Deutz, at

' Deutz, in the German Empire, have invented an Improved Gas-Motor Engine; and do hereby declare that the following description, taken in connection with the accompanying sheets of drawings, hereinafter referred to.l forms a full and exact specification of the same, wherein I have set forth the nature and principles of my said improvement, by which my invention may be,r distinguished from oth ers of a similar class, together with such parts as I claim and desire to secure by Letters Patent-that is to say:

vIn gas-motor engines as at present constructed, an explosive mixture of combustible gas and air is introduced into the engine-cylinder, Where it is ignited, resulting in a sudden development of heat and expansion of the gases, a great portion of the useful effect being lost by absorption of heat, unless specialprovisions are made for allowing the gases to expand very rapidly.

According to my present invention an intimate mixture of combustible gas or vapor and air is introduced-into the cylinder, together with a separate charge of air or other gas, that -may or may not support combustion, in such a manner and in such proportions that the particles of the combustible gaseous mix! ture are more or less dispersed in an isolated condition inthe air or other gas, so that ou ignition, instead of an explosion ensuing, the ame'will be communicated gradually from one combustible particle to another, thereby eifecting a gradual development of heat and a corresponding gradual expansion of the gases, which will enable the motive power so produced to be utilized in the most effective manner.

In order more clearly to describe my invention, I will referto the accompanying drawings, in which Figure 1 shows a longitudinal section of an engine-cylinder, A, having a piston, B, connected to a ily-wheel shaft, and a port or passage, G, for the admission of combustible gaseous mixture and air, controlled by the slide 1),'aud having also a passage, E, for the emission of the products of combustion, closed by a valve, F. Assuming. the piston to be at the end of its instroke, its bottom surface being represented by the dotted line a., wliile the slide l) is in such a position that its passage D1 establishes a communication between the outer air through the aperture D2 and the port C, then, on the piston commencing its outstroke, it will draw in atmospheric air until it arrives at the point indicated by the dotted line b, when the slide will have been moved so as to cut olf the airsuppl y and establish a communication between the passage Grpin the slide-cover, for an intimate mixture of coal-gas or petroleum vapor and air, (in such proportions that the mixture will burn of itself, but, owing to the presence of the first admitted air, will not explode,) and the port C through the passage Dl. On the continued motion of the piston, combustible gaseous mixture will consequently be drawn inuntil the piston has arrived at a point, c, when the slide will have moved in to the position shown, cutting off the gas-supply, and about to establish a communication between the small gas-dame Hand the charge in the cyl inder, for the purpose of iguiting the latter.

The combustible gaseous mixture, in entering the cylinder behind the charge of air previously admitted, will, to a certain extent, mix with the latter, the particles of the combustible mixture being close together in and near the port Grand becoming more and more dispersed in the air as they approach the piston, as indicated by the dots in the drawing, which represent the combustible particles. Thus, on the ignition of the charge iu the port G, the

gaseous mixture will at first burn with comparative rapidity, the flame spreading from particle to particle; but as the ignition extends toward the front end of the charge, it will pro ceed more and more slowly, owing to the combustible particles being farther and farther apart.

rlhe burning particles impart their heat to the surrounding air, producing a gradually. i

increasing pressure in the cylinder, which causes the pistou to complete its outstroke.

Motion being thus imparted to the fly-wheel by the piston-rod, its momentum causes the piston to perform its return stroke, whereby the products of combustion are expelled through the valve F, and, the iiy-wlieel also causing the piston to commence its next outstroke, a fresh charge of air and combustible mixture is drawn in, as before described.

In order to vary the power of the engine, the charge of combustible mixture (represented by the space a to b) may be varied, as may also the proportions of air and coal-gas or vavvgaseous charge, but a gradual development of-heat and expansion of the gases, there will 'be no such losses of effect as result in gas-engines of present construction through shocks produced by the sudden development ot' motive power, and by the absorption of heat consequent upon the inability of the gases to expand with sufficient rapidity.

The above described beneficia-l effect. of the improved mode of working will be further increased by the fact that the charge of air interposed between the combustible mixture and the piston will operateas a cushion or buffer in still further reducing the suddenness of the expansive force generated as it transmits it to the piston.

Engines operating according to my invention may either be single-acting-the return stroke being effected by the momentum ofthe ly-wheel-or they may he double-acting, a gaseous charge being introduced at each end of theeylinder. They may also operate with the gases either at `atmospheric pressure or compressed to any desired degree. In the latter case the engine may be arranged in a similar manner to that above described` the gases being compressed by any suitable known means before being introduced into the engine; but,

b y preference, I dispense with any such additlonal compressing mechanism by arranging the engine to operate in the manner I will now proceed to describe with reference to Figs. 2.

to 13 of the drawings, of which- Fig. 2 shows a side elevation; Fig. 3, aseotional plan; Fig. 4, a back-end view, and Figs. 5 to 13 details ofthe valve-gear.

The engine is here represented as being single-acting, the cylinder A being open to the atmosphere at its front end. At its closed back end it has a space, A', beyond the stroke of the piston B, which space i by preference, made conical at the end, as shown, tapering to the inlet-port O for combustible gas and air, and also communicating by the passage E with the escape-valve F, Fig. 3,- for the products of combustion.

The piston B is connected by the rod B' to thecrank-shaft I, on which is a bevel-pinion, I', in gear with a bevel-wheel, K1, on a shaft, K. 0n the other end of this shaft is a crank, K2, connected by a link, D2, to the slide D, governing the admission of gas and air to the cylinder. The gearing Il K1 is so proportioned that the crank K2 makes one-revolution', and, consequently, the slide one to-and-fro motion, while the piston makes two double strokes. 4

The mode of operating with this engine is as follows: Assuming the pistonv to be at the end of its instroke (represented by the dotted line a, Fig. 3,) and about to be moved through its outstroke by the momentum of the iiywheel M, then, the slide D (the construction of which will be presently explained) being in position to admit atmospheric air through the passage D1 and port C, air will be drawn into the cylinder until the piston has reached the point represented by the dotted line b. when, the slide having established a communication with the combustible-gas supply and the cylinder, combustible gas intimately mixed with air will be drawn in until the piston has arrived at the end of its outstroke, the position shown at Fig. 3. As before explained with reference to Fig. l, the combustible gaseous mixture, in entering, will mix to acertain extent with the air previouslyintroduced, the particles of gaseous mixture being close together at the back end of the cylinder, and more and more separated from eachother toward the front end. The slide having moved so as to close the inletport C, the pistonl isV caused, by the momentum of the fly-wheel, to

perform its instroke, whereby the charge of4 gaseous mixture and air that filled the cylinder at atmospheric pressure will be compressed into the space from the line a to the back end of the cylinder, the particles of gaseous mix- :ture remaining in much the same unequally- `distributed condition in the air as they-did bef The slide now establishes has been opened by the lever N, acted on.

by a cam, O, on the shaft K. As the p iston only moves back to the line a, it will be seen that a certain portion of the products of combustion will remain in the cylinder, and Iwill consequently mix to a certain extent with the air drawn in behind themat the next outstroke; but as the mixture of combustible gas and air afterward introduced will burn independently of the air or other gas surrounding its particles, it will be seen that the presence of such products of combustion in the charge will be of no consequence.

As before stated, the power of the engine may be regulated by regulating the quantity of combustible gas introduced at each charge.

This is effected by the gas-slide P, controlled by y the governor Q, operating on the slidingcam R as follows: Fig. 5 shows an enlarged front view vo'f-the lgas-slide; Figs. 6y and57, verticalv sections,=and Fig. v8a plan, of thesame In the casing of the. slide are lformed vtwo -passages,G1andiG, the former communicating with a'pipe, G3,\leading`tothe gas-passage G in the slide D,and the other with the gassupply-pipe G4.. 'These passages lhave small side openings,fas shown,which, when the slide is in theposition =shown in Fig. 7, both communicate'with 'the cavity of the slide P, so that gas can pass from Gr'z into G1,.and thence into=thepassageG ofthe slide D. When the slideis moved' into the position shown in Fig. 6,*this'comxnunication, and consequently the gas-supply, is cut off. a small roller, P1, upon a cam, R, which revolves with, but can slide somewhat upon, the shaft K, the raising of the slide heilig effecte'diby the cam, while'its downward motion is reffected by the spring P2. According as the cam is shifted relatively to the roller l?l by the action of the governor Q and lever Q1, (which yhas afork taking into a collar on the cam, as-shown',) t-he slide is made to establish the communication between G1 and G2 for a longer or ashorter period, thus allowing a greater or less quantity of the combustible gas for-onechargeto'pass into the cylinder A independently of'the'action of the slide D. The gasslide P is held against the face ofthe casing by a spring, P3, pressing against a cover, P, on the back of the slide.

The construction and mode of operating of the engine-slide D will be understood on reference to Figs. 10 to 13, of which Figs. l0 and 11 represent two longitudinal sections of the slide and casing on line Z Z, Fig. 12, with the slide in two different positions, and Figs. 12 and 13 show transverse sections, respectively on lilies X X and Y Y, Fig. 10.

From the previous description of the action of the engine, it will be seen that there are four strokes of the piston required for one complete operation-namely, an outstroke for drawing in the charge of combustible mixture and air, an instroke for compressing the gases, a isecond outstroke when the piston is propelled on the ignition ofthe gases, and a second instroke for expelling the products of combustion. The slide D consequently has to perform one to-and-fro motion while the piston is performingthe abovementioned four operations, for which purpose, as before stated, the slide-crank K2 makes one revolution while the engine-shaft makes two. The circle at Fig. 9 represents a diagram of the path of the crank K2, in which the part from 1 to 2 represents the motion of the slide during the time of drawing in the gaseous charge, the

'part from 2 to 3 the motion during the compression ofthe charge, 3 to 4 the motion during the working stroke, and 4 to 1 the motion during the expulsion of the products of com bustion. Figs. 10 and 11 each show two positions of the slide, Fig. 10 showing, first, its

position at the point 1 ofthe crankpath when The slide P rests with' the air-passage D1 is just about to communi- -cate with the port C, and, secondly, its position at point 2, the gas and air supply having just been cut nii'. It will be seen that in the first position the gas-passage Gr is also about to open but the beforedescribed act-ion of Vthe gas-slide P will prevent the admission of combustible gas until the requisite charge of -air is introduced. 'Figa 1l shows, lirst, the

position of the slide at the point 3 when the liame of the gasjet H is about to becoinmunicated to the gaseous charge by aismall quantity of inamed gas in the passage D3, and,

Vsecondly, itslposition at the point 4 when the escape-valve F is about to be opened.

For etlecting the ignition'of lthe charge, aY small quantity'of combustible gas is made-to pass down a pipe, S,into a recess, S,in the- Aend of the cylinder, whence it issueszthrough shown at Fig. 11.

The gas-passage G communicates with the air-passage Dl'through a number of small' openings, as shown at Fig.=:13,'so that the gas, in issuing in small divided jets into D3, becomes intimately mixed with the air therein in the requisite proportions for producing the combustible mixture before described.

The opening of the escape-valve F at the commencement of the second instroke of the piston (point 4 at Fig. 9) is e'ected by the bell-crank lever F1, connected at one end to the stem of the valve, and having at the other end a roller, F2, which is acted uponby the cam Fa on the shaft K. E'is the pipe for conducting away the products of combustion.

The governor Q is driven by bevel-gearing from the shaft K, its arms being made to move a sliding collar, Q3, up or down, thus imparting motion through the lever Ql to the cam R, as before described.

The cylinder A is, by preference, provided with a jacket, as shown.

As before stated, theengine may bearranged double-actin g by providingthe requisite valvegear for each end of the cylinder. It may also be arranged in a vertical or inclined position, instead of horizontal; and if sin gle-actin g, or if great regularity of motion be required, two or more engines may be connected to one and the same crank-shaft.

Having thus described the nature of my in vention, and in what manner the same is to be performed, I wish it to be understood that I do not claim generally the separate introduc tion of combustible gas and air into the cylin der of a gas-engine, as I am aware that is to a certain extent described in the English Patents No. 1,655 of 1857, and 335 of 1860; but,

I claim- L A gas-motor engine wherein an int-i` unite mixture of combustible gas or vapor and air is introduced into the cylinder, separate from a charge of air or other -incombustible gas, in such manner and in such proportions that the particlesot' combustible. mixture will be close together at the point of ignition, but will be more and more dispersed in the charge of air forward of that point, whereby the development of heat and the expansion or increase of pressure produced by the combustion are rendered gradual, substantially as herein described.

2. A gas-motor engine wherein an intimate mixture of combustible gas or vapor and air is introduced into the cylinder separate from and subsequent to a charge of air, such introduction being effected through an aperture or apertures in the end surface of the cylinder, in order to cause the charge of air to move forward in the cylinder as the combustible mixture is introduced, substantially as and for the purposes set forth.

3. A gas-motor engine wherein, by one outstroke of the piston, separate charges of combustible gaseous mixture and of air are drawn in to thecylinder, which charges arecom pressed by the instroke and then ignited, so as to propel the piston, which, by nits return stroke, ex-

pels the products of combustion, substantially as herein described with reference to Figs. 2 to 13 of the drawings.

4. In gas-motor engines wherein charges of combustible gas and air are introduced separately into the cylinder, regulating the power of the engine by controlling the gas-supply by means of a valve operated by a governor, substantiallyas herein described.

5. In gas-motor engines, the shaft K, driven from the engine-shaft, with crank K2, imparting motion to the slide D, cam Rffor regulating l the gas-supply, andcam' F3, for opening the escape-valve F,substantially as herein described.

6. In gas-motor engines, the combination of the cylinder A, piston B, engine-shaft I, counter-shaft K, crank K2, slide D, gas-slide P, cam R, escape-valve F, lever F1, and cam F3, all arranged and operating substantially as and for the purposes herein described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses this 1st day of June,

NICOLAUS AUGUST QTTO. Witnesses:

FRIEDRICH ALBERT SPIEGKER,Y GUsrAv KLEnmNG. i 

